仅使用BLE的设备之间的通信

<uses-permission android:name="android.permission.BLUETOOTH"/>
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
<uses-feature android:name="android.hardware.bluetooth_le" android:required="true"/>

BluetoothManager bluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
BluetoothAdapter bluetoothAdapter = bluetoothManager.getAdapter();

BluetoothAdapter.LeScanCallback leScanCallback = new BluetoothAdapter.LeScanCallback() {
    @Override
    public void onLeScan(BluetoothDevice device, int rssi, byte[] scanRecord) {
        // 处理发现的设备
    }
};

bluetoothAdapter.startLeScan(leScanCallback);

BluetoothDevice device = bluetoothAdapter.getRemoteDevice(deviceAddress);
BluetoothGatt gatt = device.connectGatt(context, false, gattCallback);

private final BluetoothGattCallback gattCallback = new BluetoothGattCallback() {
    @Override
    public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
        if (newState == BluetoothProfile.STATE_CONNECTED) {
            gatt.discoverServices();
        }
    }

    @Override
    public void onServicesDiscovered(BluetoothGatt gatt, int status) {
        // 发现服务后，可以获取服务和特征
        BluetoothService service = gatt.getService(serviceUUID);
        BluetoothCharacteristic characteristic = service.getCharacteristic(characteristicUUID);
    }

    @Override
    public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothCharacteristic characteristic) {
        // 处理特征值变化通知
    }
};

BluetoothService service = gatt.getService(serviceUUID);
BluetoothCharacteristic characteristic = service.getCharacteristic(characteristicUUID);

// 读取特征值
gatt.readCharacteristic(characteristic);

// 写入特征值
characteristic.setValue(newValue);
gatt.writeCharacteristic(characteristic);